Key Takeaways
- Shift Work Sleep Disorder (SWSD): Shift work, especially night or early morning shifts, can disrupt the body’s sleep patterns, leading to conditions like SWSD. This disorder can cause insomnia, excessive sleepiness, and persistent sleep loss.
- Negative Health Impacts: Shift work can have various negative consequences on health, including disrupted circadian rhythms, sleep deprivation, irregular sleep schedules, sleep fragmentation, increased risk of sleep disorders, impact on mental health, metabolic and cardiovascular effects, digestive issues, impaired performance and safety, and social and family disruptions.
- Strategies for Mitigation: There are several strategies to mitigate the negative effects of shift work, including creating a restful environment for sleep, avoiding drowsy driving, minimizing consecutive night shifts, managing exposure to light, exercising, eating well, and seeking medical advice if necessary.
Shift work begins before 8 a.m. and finishes after 6 p.m. or any work hours that alter your normal sleep patterns. Working shifts or other hours that disrupt your sleep patterns can cause fatigue, as they involve working during your normal rest hours.
People who suffer from Shift work sleep disorder (SWSD) or circadian rhythm sleep disorder work night, early morning, or rotating shifts. When workers with shift work disorder attempt to sleep or are excessively sleepy at work, they may experience insomnia. The average shift worker loses 1–1.5 hours of sleep each 24 hours.
Lack of sleep due to shift work can put you at an increased risk of driving or workplace accidents and an increased risk of serious health diseases over time.
Let’s delve into the comprehensive details of shift work, its impact on sleep quality, the science of circadian rhythms, and strategies to mitigate its negative impacts on sleep quality and overall health.
The Science of Sleep and Circadian Rhythms
An intricate association exists between the homeostatic physiology of the body’s internal clock and the sleep-wake cycle, which is investigated by the science of sleep and circadian rhythms. Below are some important aspects of this science:
Circadian Rhythms
- Definition: Circadian rhythms are roughly 24-hour cycles that affect physiological and behavioral functions in living things.
- Internal clock: The suprachiasmatic nucleus (SCN) in the hypothalamus controls a circadian clock, which syncs with daylight to maintain synchrony with the outside day/night cycle.
- Melatonin production: The hormone melatonin, secreted by the pineal gland, controls sleep-wake cycles. The circadian cycle influences the production of melatonin, which is typically higher at night.
Sleep Stages
Non-rapid Eye Movement (NREM) and Rapid Eye Movement Sleep (REM Sleep): NREM and REM Sleep are two categories of sleep. The former has three stages (N1, N2, and N3 being the deepest sleep stage), and the latter is linked with deep dreaming and increased brain activity.
Sleep-Wake Cycle
- Homeostatic Process: Homeostasis (the condition in which a system such as the human body is maintained in a more-or-less steady state) regulates the need for sleep based on how long one has been awake and how good sleep quality was. The longer one has been awake, the stronger the urge to sleep will be.
- Sleep Architecture: The sleep-wake cycle (circadian rhythm) follows a roughly 90 to 110-minute ultradian rhythm, consisting of Non-Rapid Eye Movement and Rapid Eye Movement Sleep cycles.
Factors Influencing Sleep
- Light Exposure: More natural light exposure during the daytime and less at night facilitates regulating the sleep-wake cycle – the circadian rhythm.
- Temperature: High temperatures are perceived as daylight by the circadian clock (24-hour sleep-wake cycle) and decreased temperatures as darkness by the clock under temperature fluctuations.
- Social and Environmental Factors: Environmental factors like temperature, nutrition, light, noise, and social cues are fed into a complex system of molecular feedback loops (molecule, cell, organism, or population) that impact sleep patterns and circadian rhythm.
Effects on Sleep Patterns
Shift work has several negative impacts on sleep patterns. These include:
Insomnia
Insomnia is a sleep disorder in which you experience difficulty falling or staying asleep. Insomnia is particularly common in individuals who suffer from shift work sleep disorder (SWSD). For example, individuals with shift work sleep disorder who work between 3 a.m. and 6 a.m. often have difficulty falling asleep, while those who work after 6 p.m. experience difficulty staying asleep.
Hypersomnia
Hypersomnia is excessive sleepiness during the day, even when you had a good night’s sleep. This usually happens with individuals with shift work sleep disorder, as they work during the night or early morning hours. Hypersomnia can be dangerous, cause accidents, and impair work performance.
Other signs of SWSD include:
- Challenge in concentrating and focus
- Fatigue and low energy
- Reduced alertness while driving and working
- Headaches
- Poor social communication, mood, and irritability
- Insomnia prevents you from getting adequate sleep
Shift Work and Its Consequences on Sleep Quality and Health
There are several negative consequences of shift work on sleep quality and overall health, which include:
Disruption of Circadian Rhythms
The human body has a 24-hour natural internal clock that dictates multiple processes. This internal clock, called circadian rhythm, regulates appetite, hormone production, sleep-wake cycles, body temperature, and other physiological processes.
Individuals who do shift work often work late nights, forcing their bodies to be awake and alert when the circadian drive for wakefulness is very low. Also, the individual feels sleepiness when the circadian drive for wakefulness is high. So, the shift workers’ circadian cycle opposes the natural biological rhythm. This results in disrupted sleep and the natural circadian rhythm.
Sleep Deprivation
Shift workers do not get sufficient quality sleep because of their erratic working hours. As a result, they experience fatigue, are sleep deprived, have weak immunity, and have poor cognitive function.
Irregular Sleep Schedule
Shift workers work in constantly changing working hours, so they do not follow a regular and consistent sleep schedule. This inconsistency disrupts their sleep-wake cycle, and they cannot sleep and wake up at the desired time.
Sleep Fragmentation
Those who work shifts are more likely to experience sleep fragmentation, which involves brief arousals. Fragmented sleep is less stimulating than consolidated sleep. It leads to excessive daytime sleepiness and diminishes the benefits of sleep as a therapeutic process.
Increased Risk of Sleep Disorders
Shift workers following an erratic sleep schedule have an increased risk of sleep disorders like insomnia, sleep-related headaches, sleep apnea, and shift work sleep disorder (SWSD). SWSD involves difficulty sleeping during the desired time frame and excessive sleepiness during work hours.
Impact on Mental Health
Shift workers suffer from chronic sleep deprivation, which can contribute to stress, severe anxiety and depression, and other mental health issues. The constant strain on the body’s circadian rhythm can reduce mental agility and mood disturbances.
Metabolic and Cardiovascular Effects
Displaced work hours, poor sleep quality, and disrupted circadian rhythms have been linked to an increased risk of hypertension, coronary heart disease, left ventricular hypertrophy and myocardial infarction, and metabolic disorders such as obesity and diabetes.
Digestive Issues
Poor sleep and disrupted circadian rhythm in shift workers are closely associated with issues related to the gastrointestinal tract. Shift workers follow erratic eating patterns, which impact the body’s natural metabolism and digestive health and can cause gastrointestinal ulcers, gastritis, and constipation.
Impaired Performance and Safety
Sleep deprivation exacerbates cognitive impairment, alleviates reaction times, reduces focus and concentration, and increases accidents in the workplace. This is especially problematic in high-strength or high-frequency industries.
Social and Family Disruptions
Shift work can disrupt social life and strain family life, as workers may find it challenging to align their schedules with their friends and family.
Strategies for Mitigating Negative Effects
Below are some tips to mitigate negative effects, recover from shift work, and catch up on sleep:
- Create a restful environment at home. Ensure the room in which you sleep is cool, quiet, and dark. Blackout curtains and earplugs can block daytime noise and keep air circulating while providing neutral background noise. Electric fans can also help create a wind-chill effect that regulates room temperature, which is optimum for quality sleep. Remove all electronic gadgets from the room to prevent any disruption in your sleep.
- Avoid drowsy driving to prevent accidents. If you feel too sleepy to drive home after your shift, take a power nap or arrange a different ride home.
- Avoid jobs that involve long commuting hours as they consume too much time and take time away from sleeping.
- Do not go for jobs that demand excessive overtime and very long shifts.
- When watching TV or listening to music while you sleep, have family members wear headphones.
- While you’re sleeping, ask your family members to avoid vacuuming and dishwashing.
- Ensure your front door has a “Do Not Disturb” sign so delivery people and friends don’t bother you.
- Take at least 48 hours off if you have continuously worked several night shifts.
- Remember to exercise and eat well. Eat little and often and choose foods that are easy to digest. Avoid caffeine in the later durations of your shift so that there are no disruptions in your sleep when it’s time to hit the hay. Steer clear of sugary foods. Keep yourself hydrated and snack on vegetables and fruits.
- Consecutive night shifts should be minimized. Night shift workers should not work more than 5 consecutive shifts within 2 weeks. 12-hour shift workers should not work more than 4 consecutive 12-hour shifts in 2 weeks.
- Avoid exposure to sunlight in the morning hours if you are planning to sleep during the daytime. While driving home from work or outside the home, wear sunglasses.
- Avoid sleeping pills and alcohol. Taking sleeping pills may disrupt your sleep pattern and may make you addicted. Make sure you speak to your doctor if you have difficulties sleeping. Drinking alcohol before bed may disturb your sleep and require you to use the bathroom more frequently during the night.
Conclusion
Shift work sleep disorder is linked to circadian misalignment resulting from a work schedule that coincides with the conventional sleep-wake cycle (circadian rhythm). The hallmark signs of shift work sleep disorder include insomnia, excessive sleepiness during waking hours, and persistent sleep loss. For an individual to be diagnosed with shift work sleep disorder, signs and symptoms must be present for at least one month, even in the face of daily attempts to obtain sufficient sleep.
SWSD can have negative impacts on your sleep patterns and overall health. However, several strategies and steps can help reduce the symptoms and establish a routine that improves sleep quality, concentration, and alertness during waking hours.
If you have severe symptoms of SWSD, it is important to consult a healthcare provider who can diagnose the condition and offer a treatment plan.
References:
- https://www.sleepfoundation.org/shift-work-disorder
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6420632/
- https://www.medicalnewstoday.com/articles/319371#1.-Stick-to-a-sleep-schedule
- https://my.clevelandclinic.org/health/diseases/12146-shift-work-sleep-disorder
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